It is known in the conveying arts to drive a load-carrying, endless belt or chain belt by disposing a hydraulic motor inside one of the end rollers which supports the belt and defines its path. This arrangement has obvious safety, compactness, simplicity and sanitation benefits. U.S. Pat. 4,013,166 Weady, is one example of this type of roller.
U.S. patent application Ser. No. 08/959,515, Hansson, is a highly refined and superior example of this technology and it is this type of hydraulic roller for which the present invention is intended. This roller is characterized by a stationary shaft disposed at one end of the roller drum, and one live shaft disposed at the opposite end of the drum. This design is advantageous over the prior art in that only one bearing assembly is required.
In the Hansson hydraulic roller, fluid is supplied to and removed from the internal hydraulic motor by way of parallel ducts machined the length of the stationary shaft that is an integral part of the end-port plate of the hydraulic motor. This arrangement greatly simplifies fluid piping requirements and consequently reduces the number of parts and hence overall cost. In keeping with the spirit of that invention, the present invention provides a simple, yet novel and unobvious fluid intake and discharge device to couple fluid into and out of the stationary shaft of the Hansson roller.
A prevalent feature of the Hansson roller lies in the ability to utilize existing, convention, self-aligning pillow-block or flange-block bearings to mount the roller to existing conveyor structures with only a small modification of the one bearing block intended for the stationary shaft. The present invention capitalizes on this feature by making this modified bearing block the means of fluid intake and discharge to the roller.